1. Field of the Invention
The present invention relates to an apparatus and method for locking the door of a vehicle, and in particular to an apparatus and method for locking a vehicle door automatically in response to starting of the vehicle and the occurrence of an additional event, such as the pressing of the brake pedal prior to placing the vehicle in gear.
2. Description of Related Art
Nearly every vehicle alarm system has an ignition controlled door lock/unlock feature that locks the doors automatically when the ignition is turned on. Automatic locking ensures that no one can open a door of the vehicle while it is moving, or enter the vehicle while it is temporarily stopped, relieving the driver of the responsibility for carrying out this safety function.
In situations where a driver might wish to start the engine and sweep snow or scrape ice of the car while the engine is warming up, however, automatic locking of the vehicle doors following starting of the engine is an inconvenience. Although the driver can exit the vehicle after door locking has taken place, if the driver later re-enters the vehicle and drives away without re-starting the engine, the doors will not be automatically locked. As a result, it would be desirable for the automatic door locking feature to take effect only after some further action is performed, and in particular some further action that is normally performed after starting of the vehicle, but not until just before the vehicle is to be driven and the driver no longer has any need to exit the vehicle.
One suitable action that may be used to trigger the automatic door locking feature, in the case of automatic transmission vehicles, is stepping on the brake of the vehicle. In such vehicles, the driver will generally step on the brake before putting the vehicle in gear, making pressing the brake an appropriate trigger for the automatic locking function.
In manual transmission vehicles, on the other hand, the driver will not generally step on the brake before moving the vehicle, in which case it should be possible to leave the door locking function dependent on ignition or starting of the vehicle rather than pressing of the brake, or to make the door locking function dependent on some action or event other than pressing of the vehicle brake, such as release of a parking brake, placing the vehicle in gear, or release of a clutch pedal while the vehicle is in gear.